At least 3,000 IS fighters may have infiltrated Turkey post being pushed out of Syria's Kobani

At least 3,000 Islamic State (IS) militants have reportedly infiltrated Turkey post being driven out of the border town of Kobani.

According to The Daily Express, the news was broken by a Turkish newspaper that published an internal memo from MIT, Turkey's National Intelligence Organization. It said that IS militants, including senior commanders plotting terror attacks in Turkey, are believed to have infiltrated the nation and hidden in safe houses.

The memo warned that militants with great expertise in carrying out suicide and bomb attacks were preparing to attack Istanbul and Ankara missions of coalition forces who intervened in Syria.

The report said that Istanbul holds a special significance for the IS as they believe that the ancient city will have a pivotal role to play in the creation of a world-wide caliphate.

The IS strictly adheres to a variety of Islam whose references to the path to the Day of Judgment have impacted IS' military and geographical strategy to a very large extent.

According to their beliefs, the IS awaits the army of "Rome" and a defeat at Dabiq in Syria that will kickstart the countdown to the apocalypse.

They believe that the armies of Rome and the armies of the IS will meet in Istanbul, the historic capital of the Eastern Roman empire.

The historical city will be ransacked by the group, who will then proceed towards Europe.